There are an increasing number of devices where it is desired or needed to be able to detect and quantify an acceleration (i.e., a linear acceleration) force and/or a rotational force that is applied to the device. In particular, many game-playing devices and portable electronic devices need to be able to detect rotation and movement of the device. For example, a number of devices use accelerometers to orient the display of an image on a display screen to match the orientation in which the device is held, i.e., switching between portrait and landscape modes depending upon how the device is held. Such devices include some tablet personal computers (PCs), smart phones, and digital cameras
Currently, microelectromechanical system (MEMS) accelerometers and gyroscopes are generally used in these devices for detecting and quantifying acceleration (linear motion) and rotational motion. For example, the current version of the SONY WII MOTIONPLUS® expansion device for the WII® Remote video game controller for the WII® home video game system uses a dual-axis tuning fork gyroscope and a single-axis gyroscope which can determine rotational motion.
Gyroscopes are also useful for “dead reckoning” of a device. That is, a gyroscope can be used to track a device's movements and turns, for example to show the device's location on a map—which may be particularly useful when the device is inside a building or underground or otherwise isolated from Global Positioning System (GPS) signals.
It would be desirable, therefore, to provide a device that can measure both acceleration and rotation. It would also be desirable to provide a method of detecting both acceleration and rotation.